Wireless transmitter



May'8, 1923. 1,454,598 w. T. DlTCHAM WIRELESS TRANSMITTER Filed Dec. 18, 1920 8140 an l'o z William Z 91mm Jaw ' Patented May 8, W23,

tartan stares teases earner WELIAH TEODOEE DITCBLAIM, F TWICKEN'HAM, ENGLAND, ASSIGNOR T0 RADIO COBPOBAE'ION OF AMERICA, ()F m YQRK, N. Y., A CORPORATION OF DELAWARE.

Application filed December is, 1920. serial no. 431,582.

To all whom it may concem:

Be it known that 1, WILLIAM THEODORE Drromar a subject of GreatBritain, residing at Kildary, Lebanon Park, Twickenham, in the county of Middlesex, England,

have invented certain new and useful improvements in Wireless Transmitters, of which the following is a specification accompanied by drawings.

The object of this invention is to provide an improved valve transmitter in which the transmission of the interfering noises known as key clicks may be obviated and the valve or valves may be relieved of the full load during the spacing periods of the Morse characters.

According to this invention I connect in the primary power circuit of a valve transmitter a choke coil if the primary current at is alternating, or a resistance if the primary current is direct, and I provide a key or switch by means of which this choke coil or resistance may be shortcircuited for the purpose of signaling. The choke or resistance should be of such a value that when it is not shortcircuited the valve will continue to oscillate but will only generate a small current compared to its normal working current. Thus signals can be transmitted by to varying the strength of the oscillations without stopping their production or sensibly varying their frequency.

My invention is illustrated in the accompanyin diagram, in which C is an iron cored c oke coil inserted in the circuit of an alternator A and K is a key by which it can be shortcircuited. T is a transformer, R a rectifier and V the oscillating valve.

Having now particuarly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is 1. In a wireless transmitter, the combination of an oscillating valve, a circuit containing a source of alternating current supply for said valve, a rectifier interposed between said source of supply and said valve, an impedance connected in said circuit, and means for short circuiting said impedance.

2. In a wireless transmitter, the combination of an oscillating valve, a circuit containing a source of alternating current supply for said valve, a rectifier interposed between said source of supply and said valve, a choke coil connected in said circuit, and means for short circuiting said choke coil.

3. The combination claimed in claim 1 in which said impedance is of such value that the valve will continue to oscillate at substantially the same frequency regardless of 60 the position of the short circuiting means.

WILLIAM rnnononn DITCHAM. 

